Fluorochemical compositions for the treatment of substrates such as leather, textiles and paper are well known and are used to impart various properties to the substrate such as water and/or oil repellency, waterproofness, stain release, anti-staining etc. For example, U.S. Pat. No. 5,276,175 discloses isocyanate derivatives comprising fluorochemical oligomers. In particular, the disclosed fluorochemical compositions comprise fluorinated compounds, wherein the fluorinated compound comprises a fluorochemical oligomeric portion, an organic moiety, and a group that can impart soft hand, stain release, water repellency, or a durable property when the compound is applied to a fibrous substrate, wherein the fluorochemical oligomeric portion is bonded to the organic moiety through an isocyanate-derived linking group. Substrates so treated are shown to exhibit particularly durable and abrasion-resistant oil and water repellency. Further, in one of the examples there is shown a fluorochemical composition that is based on a condensate of a tri-isocyanate, a fluorochemical oligomer and a methoxypolyethyleneoxide glycol. For this composition stain release properties are demonstrated on a polyester/cotton blend fabric.
U.S. Pat. No. 5,350,795 discloses fluorochemical compositions for treating textile fibers and fabrics to impart oil and water repellency without thermal treatment. The compositions comprise an aqueous, substantially organic solvent free, solution or dispersion of (a) a fluorochemical acrylate copolymer comprised of a fluorinated acrylate monomer, polyalkylene glycol acrylate or methacrylate, or polyalkylene glycol diacrylate or dimethacrylate; and (b) a polyalkoxylated polyurethane having pendant perfluoroalkyl groups comprised of an aliphatic or aromatic tri- or higher order isocyanate, a fluorinated alcohol, amine, or mercaptan, and a poly(oxyalkylene) diol or dithiol.
U.S. Pat. No. 4,788,287 and U.S. Pat. No. 4,792,354 disclose a water and oil repellent compound having at least two terminal segments and an intermediate segment connecting the terminal segments that has a molecular weight of from 800 to 20,000. Each terminal segment of the compound contains at least one polyfluoroalkyl group connected by a --CONH-- linking group, the intermediate segment is a urethane oligomer containing at least two --CONH-- linking groups in one molecule, and the terminal segments and intermediate segment are connected by a --CONH-- linking group. The urethane oligomer of U.S. Pat. No. 4,792,354 further contains a hydrophilic molecular chain.
U.S. Pat. No. 5,491,261 discloses di-, tri- and poly-perfluoroalkyl-substituted alcohols and acids and derivatives thereof which are prepared from perfluoroalkyl iodides and di-, tri- or polyalkyl alcohols or acids. They can be reacted with isocyanates, epoxy compounds, anhydrides, acids or acid derivatives to prepare a great variety of oil- and water-repellent compositions.
Fluorochemical compositions are also used to facilitate stain or soil release from a substrate such as for example a fabric. Routine treatments of fabrics with modifying additives such as softeners, stiffeners and lubricants to impart desired properties to a commercial fabric typically increase the oleophilicity of the fabric, thereby significantly increasing its tendency to accept oily stains and reducing its ability to release such stains after laundering. Fluorochemical compositions based on a mixture of a fluorinated compound and a non-fluorinated hydrophilic compound or a chemical "hybrid" compound that contains fluorochemical oleophobic segments ("F") and non-fluorinated hydrophilic segments ("H") are known to act as stain release compositions since they provide oil repellency during normal wear and inhibit wicking or diffusion of oily soils into the fabric or fiber bundles as well as facilitate soil release during laundering.
U.S. Pat. No. 3,574,791 discloses a block-copolymer consisting of F and H segments for use as a stain-release agent. The "F"-segments are substantially free of hydrophilic groups whereas the "H" segments are substantially free of fluorinated aliphatic groups. It is taught that due to this segmentation, the polymer is "autoadaptable", i.e., a fabric treated with the polymer will be an oil and water repellent in an atmospheric environment, and when laundered in water, it will become hydrophilic so stain removal becomes possible. Various possible chemical linkages are contemplated for connecting the "F" and "H" segments, including a urethane linkage derived from the reaction of an alcohol and an isocyanate.
U.S. Pat. No. 5,509,939 discloses a fluorochemical composition to impart soil release properties to a substrate. The fluorochemical composition comprises urea-linkage-containing-alkoxypolyoxyalkylene fluorocarbamates prepared by reacting (a) at least one polyisocyanate which contains at least three isocyanate groups with (b) at least one fluorochemical reagent which contains one functional group which has at least one hydrogen atom and at least two carbon atoms each of which contains at least two F atoms, (c) at least one hydrophilic, water-solvable reagent which contains a single functional group which has at least one reactive hydrogen atom, (d) at least one reagent which contains one reactive hydrogen and which on reaction with an isocyanate group, yields functionality which has abeyant chemical reactivity with fibrous substrates, and then reacting the product with water such that reactants (b), (c) and (d) are reacted with 55% to 95% of the isocyanate groups, and water with the remainder.
Despite the many fluorochemical compositions known to impart stain release properties to a substrate, there continues to be a desire for fluorochemical compositions that have improved properties. Desirable properties for fluorochemical compositions include easy cleanability of natural fiber substrates such as cotton and blends of cotton and polyester, particularly with respect to oil-type stains (dirty motor oil, vegetable oil) and water based stains (tea, coffee); low manufacturing cost; high storage stability; easy emulsifiability and high performance even if applied in low quantities. It is further desirable that the fluorochemical compositions provide good stain repellency and oil and/or water repellency properties to the substrate.